Author: Clarence Errol Ferree

Publisher: Forgotten Books

Published: 2018-02-03

Total Pages: 116

ISBN-13: 9780484173735

Excerpt from Some Areas of Color Blindness of an Unusual Type in the Peripheral Retina While a red light does not give green contrast sensation, it does produce an effect on a neighboring field which raises the threshold or diminishes the sensitivity to red. That is, a gray ring on a red ground appears gray but an amount of red can be added to it without being sensed which is supraliminal when red is not present in the sur rounding field. In other words a physiological induction seems to be present which inhibits the complementary excitation although the induced excitation does not itself arouse sensation. We have here, therefore, another evidence that the complementary and induction relations between red and green are intact, the ability of the green excitation to arouse sensation alone being absent. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.